Johachidolite - Sold

Pyant Gyi mine

Pein Pyit

Mogok

Mandalay Division

Burma

3.2 by 2.7 by 1.8 cm – Thumbnail specimen (fits into a 2.5 cm cube)

Johachidolite is a calcium aluminum borate mineral. The mineral name follows from its discovery in the Jōhachidō District (now Sangpal-tong) of North Korea (Iwase & Saito, 1942). Crystal structure solution by Moore & Araki (1972) simplified the ideal formula to CaAlB3O7, which led Aristarain & Erd (1977) to formally redefine the species with approval from the International Mineralogical Association.

Amongst a parcel of Burmese gems examined in 1998, an exotic yellow 14 carat stone turned out be johachidolite. This Burmese stone represented a second world occurrence of the species! The geological setting remained a mystery until later finds in 2005-2007 brought further material to light. Peretti et al., (2007) studied hundreds of pieces and arranged a visit to the occurrence. Most johachidolite occurs as incomplete crystals in orthoclase and sodalite matrix with phlogopite.

Johachidolite here forms a crude crystal in orthoclase matrix, with minor phlogopite. The johachidolite shows a single crystal face 26 by 12 mm, on a larger mass of orange johachidolite. This is a very large grain of the mineral showing excellent color. A good example!